DESCRIPTION (Investigator's Abstract): In treating glaucoma, clinicians attempt to lower patient's intraocular pressure (IOP). The IOP is not constant however, and a single measurement taken during a visit to the ophthalmologist may be unreliable. The desireable measurement of the IOP at the patient's home has been hampered by the lack of an instrument. A self-tonometer, recently developed and implemented in clinical research, has been cited among the progresses in the priority areas set in the NEI National Plan. The goal of this proposal is to make the self-tonometer available to the ophthalmic community by converting it into a commercial product. Phase II is designed to complete the implementation of a microcomputer; write programs to analyze the readings and provide immediate feedback to the patient; allow for battery operation; upgrade the sensor head into a manufacturable component; develop a disposable probe; write a program for office computers to download the data and present diurnal IOP curves. The self-tonometer will be evaluated in the clinics of ten independent glaucoma experts; its readings will be correlated with those of the Goldmann tonometer; and its application to monitoring the IOP of glaucoma patients at their home and work place will be assessed. Phase III will be dedicated to manufacturing the instrument and obtaining FDA approval for its commercial use.